Chrysanthemum plant named Yellow Diamond

ABSTRACT

A Chrysanthemum plant named Yellow Diamond particularly characterized by its flat capitulum form; decorative capitulum type; yellow ray floret color; diameter across face of capitulum of 127 to 139 mm when fully opened, when grown as a pinched disbudded pot mum; photoperiodic flowering response to short days of 53 to 57 days; plant height, with 16 long days after sticking unrooted cuttings, and with 1 application of 2500 ppm B-9 SP, ranges from 18 to 25 cm when grown as a pinched pot mum with 4 cuttings in a 15 cm pot; spreading branching pattern, with each plant having 5 to 6 laterals after pinch, and its recommended grown as a disbud pot mum.

The present invention comprises a new and distinct cultivar ofChrysanthemum, botanically known as Dendranthema grandiflora, andreferred to by the cultivar name Yellow Diamond.

Yellow Diamond, identified as 5800 (85-789F02), is a product of amutation induction program. The new cultivar was discovered and selectedby Cornelis P. VandenBerg on Nov. 18, 1990 in a controlled environmentin Salinas, Calif., as one flowering plant within a flowering blockestablished as rooted cuttings from stock plants which had been exposedas unrooted cuttings to an X-ray source of 2000 rads in Fort Myers,Fla., on May 31, 1990. The irradiated parent cultivar, identified as5194 (85-789B02), was a selection from an earlier mutation breedingprogram, in which the grandparent, an unnamed seedling, identified as4149 (85-789002) was irradiated to intensify and possibly change thecolor of this unnamed seedling. The grandparent seedling 4149(85-789002) is described as a flat decorative disbud pot mum with a verylight pink ray floret color, a flowering response period of 54 to 62days after start of short days, a plant height of 23 to 30 cm with oneapplication of 2500 ppm B-9 SP, a spreading branching habit with 5 to 6laterals after pinch and a diameter of capitulum of 127 to 155 mm whenfully opened. This cultivar was discovered and selected as one floweringplant in August 1985 by Cornelis P. VandenBerg from the progeny of across made in 1984. The female parent was the cultivar identified asCharm, a pink flat decorative disbud pot mum, disclosed in U.S. PlantPat. No. 5,502. The male parent was an unnamed seedling, identified as0668 (82-051014) and described as a yellow flat daisy disbud pot mumwith many ray florets.

The irradiation program resulting in Yellow Diamond had as its primaryobjective the expansion of color ranges of the unnamed grandparentcultivar. The grandparent cultivar had a very light pink ray floretcolor, which color as regarded as not commercially acceptable. Becauseall other traits of this cultivar were outstanding, an attempt was madeto obtain different ray floret colors, while maintaining all othertraits of the grandparent cultivar. The irradiation program comprisedirradiating cuttings of the grandparent cultivar 4149 (85-789002) atirradiation levels of 1500, 1750 and 2000 rads. A total of 1264 cuttingsharvested from a total of 225 irradiated plants were planted on November9 and November 30. Of these, 24 initial selections were made, whichselections were then revegetated and reflowered. Four consecutiveflowerings resulted in discarding 19 of the original 24 selections onNov. 9, 1988. Four selections were retained and one selection,identified as 6927, was reselected under code 5194 (85-789B02) aspossible introduction, to be further tested in flowering programs inSalinas, Calif., and in Leamington, Ontario, Canada. These floweringsresulted in discarding three out of the five selections on Apr. 26,1990, on Jul. 10, 1990, and on Dec. 7, 1990, and the decision tocommercially introduce one remaining selection as White Diamond. WhiteDiamond was commercially introduced in April 1991, and is disclosed inU.S. Plant Pat. No. 8,059. The one other remaining selection, 5194, withyellow ray floret color, was exhibiting bronze overtones, and thedecision was made to irradiate 5194, with the object to obtain a clearyellow ray floret color, without the bronze overtones.

The irradiation program comprised irradiating cuttings of the parentcultivar 5194 (85-789B02) at irradiation levels of 1500, 1750 and 2000rads. A total of 1265 cuttings harvested from a total of 225 irradiatedplants were planted on Sep. 17 and Sep. 14, 1990. Of these, 16 initialselections were made, which selections were then revegetated andreflowered. Four consecutive flowerings resulted in discarding 13 of theoriginal 16 selections on Aug. 19, 1991. Three selections were retainedto be further tested in our Salinas, Calif., flowering programs. Theseflowerings resulted in the decision to commercially introduce oneremaining selection as Yellow Diamond, because of the clear yellow rayfloret color with no bronze overtones. The two other remainingselections were maintained to be further tested in low light winterflowerings in comparison with Yellow Diamond.

The first act of asexual reproduction of Yellow Diamond was accomplishedwhen vegetative cuttings were taken from the initial selection inJanuary 1991 in a controlled environment in Salinas, Calif., bytechnicians working under supervision of Cornelis P. VandenBerg.

Horticultural examination of controlled flowerings of successiveplantings has shown that the unique combination of characteristics asherein disclosed for Yellow Diamond are firmly fixed and are retainedthrough successive generations of asexual reproduction.

Yellow Diamond has not been observed under all possible environmentalconditions. The phenotype may vary significantly with variations inenvironment such as temperature, light intensity and daylength, without,however, any variance in genotype.

The following observations, measurements and comparisons describe plantsgrown in Salinas, Calif., under greenhouse conditions which approximatethose generally used in commercial greenhouse practice.

The following traits have been repeatedly observed and are determined tobe basic characteristics of Yellow Diamond, which, in combination,distinguish this Chrysanthemum as a new and distinct cultivar:

1. Flat capitulum form.

2. Decorative capitulum type.

3. Yellow ray floret color.

4. Diameter across face of capitulum of 127 to 139 mm when fully opened,when grown as a pinched disbudded pot mum.

5. Photoperiodic flowering response to short days of 53 to 57 days.

6. Plant height, with 16 long days after sticking unrooted cuttings, andwith 1 application of 2500 ppm B-9 SP, ranges from 18 to 25 cm whengrown as a pinched pot mum with 4 cuttings in a 15 cm pot.

7. Branching pattern is spreading, each plant having 5 to 6 lateralsafter pinch.

8. Recommended as disbud pot mum.

The accompanying photographic drawing is a color photograph of YellowDiamond grown as a pinched disbudded pot mum with 4 cuttings in a 15 cmpot, with the colors being as nearly true as possible with illustrationsof this type.

Of the commercial cultivars known to the inventor, the most similar incomparison to Yellow Diamond is the cultivar identified as WhiteDiamond, disclosed in U.S. Plant Pat. No. 8,059. All traits of YellowDiamond are similar to those of White Diamond except for ray floretcolor, diameter of capitulum, flower form and flowering response toshort days. White Diamond has a white ray floret color with a creamcenter of the flower, while Yellow Diamond has a clear yellow ray floretcolor. The diameter of capitulum of Yellow Diamond is 6 to 20 mm smallerthan the diameter of White Diamond. White Diamond has a very flat andformal flower form, while the flower form of Yellow Diamond is lessformal and slightly reflexing when fully open. When grown side by side,Yellow Diamond is one to three days slower in flowering response toshort days than White Diamond.

In the following description color references are made to The RoyalHorticultural Society Colour Chart. The color values were determined onplant material grown as a pinched disbudded pot mum in Salinas, Calif.,on Aug. 19, 1991.

Classification:

Botanical.--Dendranthema grandiflora cv Yellow Diamond.

Commercial.--Flat decorative disbud pot mum.

INFLORESCENCE

A. Capitulum:

Form.--Flat.

Type.--Decorative.

Diameter across face.--127 to 139 mm when fully opened.

B. Corolla of ray florets:

Color (general tonality from a distance of three meters).--Yellow.

Color (upper surface).--7A to 7C.

Color (under surface).--7B.

Shape.--Straight, cross section concave.

C. Corolla of disc florets:

Color (mature).--13B to 14B.

Color (immature).--144B to 144C.

D. Reproductive organs:

Androecium.--Present on disc florets only; very few disc florets, nopollen.

Gynoecium.--Present on both ray and disc florets.

PLANT

A. General appearance:

Height.--18 to 25 cm when grown as a pinched pot mum with 16 long daysprior to start of short days, with 1 application of 2500 ppm B-9 SP.

Branching pattern.--Spreading and prolific, with 5 to 6 laterals afterpinch.

B. Foliage:

Color (upper surface).--147A.

Color (under surface).--147B.

I claim:
 1. A new and distinct Chrysanthemum plant named Yellow Diamond,as described and illustrated.